The correct interpretation of results in the treatment of bronchial asthma presents an exceedingly difficult problem. So chronic, so distressing, so intractable is this malady that any new procedure which appeals to the sufferer and carries with it the slightest hope of relief may produce at least a temporary amelioration of the symptoms. We must be careful, therefore, not to fall into the error of overestimating the value of any new treatment. It is only by repeated observations over a long period of time that any conclusive interpretation can be made. However, six successive cases of bronchial asthma responded so favorably, in our opinion, to the repeated subcutaneous injections of autogenous defibrinated blood as to warrant at least a preliminary report of the cases, the treatment and the theoretical considerations that prompted us to employ this method of therapy and that may help to explain the results obtained.